Background. To assess the peeling forces exerted by different calibers of microsurgical forceps on an experimental model of epiretinal membrane. Methods. A model of epiretinal membrane was constructed using thin cellulose paper and heptanes-isopropyl alcohol 1% mixture. The model was mounted on a force censoring device. Subsequently, flaps were created with three different microsurgical forceps of different calibers. We recorded the number of attempts, the duration of the event, and the pushing and the pulling forces during the peeling. The results were compared by a one-way ANOVA and a Fisher unprotected least significant difference test with an alpha value of 0.05 for statistically significance. Results. There was a statistical significant difference on the pulling and pushing forces between the 25 gauge (13.79？mN; ？13.27？mN) and the 23 (6.63？mN; ？5.76？mN) and 20 (5.02？mN; ？5.30？mN) gauge, being greater in the first ( ). There were no differences in the duration of all events, meaning that all the forces were measured within the same period of time. Conclusions. The 25 gauge microsurgical forceps exerted the greatest mechanical stress over our simulated epiretinal membrane model and required more attempts to create a surgical suitable flap. The clinical implication of this finding is still to be determined. 1. Introduction The surgical resolution of vitreoretinal diseases involves the micromanipulation of very fragile structures. A successful surgery depends upon the surgeon possessing a particular set of skills that include precise manual dexterity, fine visual-motor coordination, and improvisation capabilities, acquired after long hours of training [1, 2]. Imprecise movements due to tremor, poor visibility, and fatigue often may result in tissue damage which can be irreversible and sight-threatening depending on location [3, 4]. Macular surgery is one such scenario in which external factors (patient movements and surgical instruments), along with the surgeon’s dexterity, may influence the outcome [5]. Macular hole (MH) repair, epiretinal membrane (ERM), and internal limiting membrane (ILM) peeling are perfect examples where the application of unknown forces to the tissues may lead to hemorrhage, tearing, and potential irreversible visual loss [5–7]. With the introduction of minimally invasive surgical techniques (23 and 25 gauge vitrectomy), macular diseases are addressed surgically more often and earlier than ever [5]. Along with the change in surgical paradigm, several aspects of retinal instruments have undergone further refinement [8, 9].
References
[1]
M. Balicki, A. Uneri, I. Iordachita, J. Handa, P. Gehlbach, and R. Taylor, “Micro-force sensing in robot assisted membrane peeling for vitreoretinal surgery,” in Medical Image Computing and Computer-Assisted Intervention, vol. 6363 of Lecture Notes in Computer Science, pp. 303–310, 2010.
[2]
B. A. E. Mazinani, A. Rajendram, P. Walter, and G. F. Roessler, “Does surgical experience have an effect on the success of retinal detachment surgery?” Retina, vol. 32, no. 1, pp. 32–37, 2012.
[3]
B. Gonenc, M. A. Balicki, J. Handa, et al., “Evaluation of a micro-force sensing handheld robot for vitreoretinal surgery,” in Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS '12), pp. 4125–4130, Vilamoura-Algarve, Portugal, October 2012.
[4]
J.-P. Hubschman, J.-L. Bourges, W. Choi et al., “The microhand: a new concept of micro-forceps for ocular robotic surgery,” Eye, vol. 24, no. 2, pp. 364–367, 2010.
[5]
T. L. Jackson, P. H. Donachie, J. M. Sparrow, and R. L. Johnston, “United Kingdom National Ophthalmology Database Study of Vitreoretinal Surgery: report 2, macular hole,” Ophthalmology, vol. 120, no. 3, pp. 629–634, 2013.
[6]
A. Ang, D. R. J. Snead, S. James et al., “A rationale for membrane peeling in the repair of stage 4 macular holes,” Eye, vol. 20, no. 2, pp. 208–214, 2006.
[7]
S. Kusuhara, S. Ooto, D. Kimura et al., “Outcomes of 23- and 25-gauge transconjunctival sutureless vitrectomies for idiopathic macular holes,” British Journal of Ophthalmology, vol. 92, no. 9, pp. 1261–1264, 2008.
[8]
R. B. Bhisitkul and C. G. Keller, “Development of microelectromechanical systems (MEMS) forceps for intraocular surgery,” British Journal of Ophthalmology, vol. 89, no. 12, pp. 1586–1588, 2005.
[9]
K. Ikuta, T. Kato, and S. Nagata, “Development of micro-active forceps for future microsurgery,” Minimally Invasive Therapy and Allied Technologies, vol. 10, no. 4-5, pp. 209–213, 2001.
[10]
P. J. Ferrone and K. M. Chaudhary, “Macular epiretinal membrane peeling treatment outcomes in young children,” Retina, vol. 32, no. 3, pp. 530–536, 2012.
[11]
I. U. Scott, H. W. Flynn Jr., N. Acar et al., “Incidence of endophthalmitis after 20-gauge vs 23-gauge vs 25-gauge pars plana vitrectomy,” Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 249, no. 3, pp. 377–380, 2011.
[12]
A. Haas, G. Seidel, I. Steinbrugger et al., “Twenty-three-gauge and 20-gauge vitrectomy in epiretinal membrane surgery,” Retina, vol. 30, no. 1, pp. 112–116, 2010.
[13]
B. J. Ernst, R. Velez-Montoya, D. Kujundzic, E. Kujundzic, and J. L. Olson, “Experimental measure of retinal impact force resulting from intraocular foreign body dropped onto retina through media of differing viscosity,” Clinical & Experimental Ophthalmology, 2012.
[14]
M. Kita and M. F. Marmor, “Retinal adhesive force in living rabbit, cat, and monkey eyes: normative data and enhancement by mannitol and acetazolamide,” Investigative Ophthalmology and Visual Science, vol. 33, no. 6, pp. 1879–1882, 1992.
[15]
A. S. Jagtap and C. N. Riviere, “Applied force during vitreoretinal microsurgery with handheld instruments,” in Proceedings of the 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC '04), pp. 2771–2773, San Francisco, Calif, USA, September 2004.
[16]
S. Sunshine, M. Balicki, X. He, et al., “A force-sensing microsurgical instrument that detects forces below human tactile sensation,” Retina, vol. 33, no. 1, pp. 200–206, 2013.
[17]
I. Kuru, B. Gonenc, M. Balicki, et al., “Force sensing micro-forceps for robot assisted retinal surgery,” in Proceedings of the 34th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC '12), pp. 1401–1404, San Diego, Calif, USA, 2012.
